Secure computation is a method to obtain a certain calculation result without restoring concealed values (see Non-patent Literature 1, for example). The method described in Non-patent Literature 1 performs concealing in which fragments of a value are distributed to three secure computation devices. The three secure computation devices perform calculations in cooperation, whereby the results of calculations such as addition and subtraction, constant addition, multiplication, constant multiplication, logical operation (NOT, logical AND, logical OR, exclusive OR), and data format conversion (integer, binary) can be maintained, without restoring a concealed value, in a state distributed to the three secure computation devices, that is, in a concealed state.
Non-patent Literature 2 recites a method of mapping these elements in accordance with a table by secure computation. In the method described in Non-patent Literature 2, a map in which an element (value) in a concealed table is replicated in the same sequence is realized in secure computation.